Candy Corn or Candy Corn-not

Happy Halloween again everyone! Let me start this blog off with a little bit of imagery.

Let’s go back in time to when you were about twelve years old on Halloween day. It’s around 10 pm (you came home early because this year, Halloween falls on Sunday and you have school the next day), you’re exhausted after knocking on hundreds of strangers’ doors, in a sugar-fueled trance repeating those hypnotizing words, “trick-or-treat”, until your mouth has run dry. Your pillowcase is packed to the brim with candy (not to mention the other 2 bags you’ve already filled and dumped into mom and dad’s van). You empty the contents of those bags onto the carpet to get ready to sort them from, “why do people even give this out?” to “oh my goodness, a king-sized Snickers^® bar!”. You look down at all your candy and to your dismay your eyes lock onto that bag of yellow, orange, and white triangular looking bits that do not look even a little like corn, realizing that some strangers had the audacity to drop some Candy Corn^® into your bag.

Anyways, I digress, let’s move on from solely talking about Candy Corn^® and ask the question: what is really in candy? One thing I have noticed is that the nutritional facts on the back of the candy bag can be somewhat misleading. Specifically, in Figure 1, I took a picture of the nutritional facts of Skittles^®, and we see that per quarter cup of Skittles^®, there are 30 grams of sugar. Not only is this an alarming amount of sugar, but it is quite ambiguous. Unwillingly, our minds are flooded with questions such as: “what kind of sugars are in there?”, or “is there a certain percentage of sugars relative to one another?”. Who knows, maybe there’s a secret formula to all of this.

FIGURE 1. NUTRITIONAL FACTS OF SKITTLES®.

For the purposes of this blog, I will be focusing on sucrose and glucose, partly due to some of their conveniently identifiable signals via ¹H nuclear magnetic resonance (NMR). It turns out that there are a wide variety of sugars found in candy (I mean, they do make up 75% of a serving).

Shown in Figure 2 is a stacked plot of the ¹H NMR spectra of glucose (maroon trace) and sucrose (blue trace). Their unique peaks are highlighted in red in both the spectra and the molecular structures.

Figure 2. ¹H (60 MHz) stacked spectra of glucose (maroon trace) and sucrose (blue trace) in deuterium oxide (D₂O) and their respective structures with the protons of interest highlighted in red.

In this blog post, I analyzed 4 different candies: Candy Corn (gross), Skittles^®, Jellybeans, and Sour Patch Kids^®. Figure 3 shows a stacked plot of the ¹H NMR spectra, where approximately 20 mg of each candy was dissolved in D₂O and analyzed.

Figure 3. ¹H (60 MHz) stacked spectra of Candy Corn^® (maroon trace), Skittles^® (purple trace), jellybeans (blue trace) and Sour Patch Kids^® (green trace). The intensities were normalized using the sucrose peak.

These ¹H spectra provide us with an easy way to determine the relative ratios of sucrose to glucose in these products. These ratios are tabulated in Table 1 for each candy, demonstrating that this can vary significantly across different products.

Table 1. Determination of sucrose to glucose ratios of Candy Corn, Skittles^®, Jellybeans and Sour Patch Kids^®.

With a relative ratio of glucose to sucrose of approximately 48%, Sour Patch Kids^® seem to have the highest glucose content, whereas Candy Corn^® has the least with around 9%. We decided to conduct a quantitative NMR (qNMR) experiment on the Candy Corn^®, by adding an internal calibrant (maleic acid, 99.94% purity) to determine what portion of its mass is made of sucrose and glucose. Figure 4 shows the spectra of accurately weighed Candy Corn^® and maleic acid, dissolved in D₂O, as well as their respective integration values.

Figure 4. ¹H (60 MHz) spectra of Candy Corn^® and maleic acid in D₂O.

Using the maleic acid peak at 6.48 ppm, we determined that the masses of sucrose and glucose that made up our 101.56 mg sample of Candy Corn^® were 20.30 mg and 1.63 mg, respectively. Therefore, approximately 20.3% of Candy Corn^® is made of sucrose and glucose! Well, that was probably a little more than you needed to know about your candy and Candy Corn^® specifically, but if you would like to learn more about sugar and even artificial sweeteners, click here! As always, if you have any questions at all, please do not hesitate to contact us. Have a sweet - candy corn free - and safe Halloween everyone!